Make ShellAppMonitor and ShellAppSystem singletons, remove unused code in appDisplay

We shouldn't create multiple instances of either.  Also remove a bit
of unused code in appDisplay.

js/misc/appInfo.js

@@ -104,7 +104,7 @@ function getAppInfo(appId) {
 //
 // Return value: the list of #AppInfo
 function getMostUsedApps(count) {
-    let appMonitor = new Shell.AppMonitor();
+    let appMonitor = Shell.AppMonitor.get_default();
 
     // Ask for more apps than we need, since the list of recently used
     // apps might contain an app we don't have a desktop file for

js/ui/appDisplay.js

@@ -18,32 +18,6 @@ ENTERED_MENU_COLOR.from_pixel(0x00ff0022);
 const MENU_ICON_SIZE = 24;
 const MENU_SPACING = 15;
 
-// TODO - move this into GConf once we're not a plugin anymore
-// but have taken over metacity
-// This list is taken from GNOME Online popular applications
-// http://online.gnome.org/applications
-// but with nautilus removed (since it should already be running)
-// and evince, totem, and gnome-file-roller removed (since they're
-// usually started by opening documents, not by opening the app
-// directly)
-const DEFAULT_APPLICATIONS = [
-    'mozilla-firefox.desktop',
-    'gnome-terminal.desktop',
-    'evolution.desktop',
-    'gedit.desktop',
-    'mozilla-thunderbird.desktop',
-    'rhythmbox.desktop',
-    'epiphany.desktop',
-    'xchat.desktop',
-    'openoffice.org-1.9-writer.desktop',
-    'emacs.desktop',
-    'gnome-system-monitor.desktop',
-    'openoffice.org-1.9-calc.desktop',
-    'eclipse.desktop',
-    'openoffice.org-1.9-impress.desktop',
-    'vncviewer.desktop'
-];
-
 const MAX_ITEMS = 30;
 
 /* This class represents a single display item containing information about an application.
@@ -196,8 +170,8 @@ AppDisplay.prototype = {
         // map<itemId, array of category names>
         this._appCategories = {};
 
-        this._appMonitor = new Shell.AppMonitor();
-        this._appSystem = new Shell.AppSystem();
+        this._appMonitor = Shell.AppMonitor.get_default();
+        this._appSystem = Shell.AppSystem.get_default();
         this._appsStale = true;
         this._appSystem.connect('changed', Lang.bind(this, function(appSys) {
             this._appsStale = true;

src/shell-app-monitor.c

@@ -912,3 +912,19 @@ on_enable_monitoring_key_changed (GConfClient *client,
 {
   update_enable_monitoring ((ShellAppMonitor *) monitor);
 }
+
+/**
+ * shell_app_monitor_get_default:
+ *
+ * Return Value: (transfer none): The global #ShellAppMonitor instance
+ */
+ShellAppMonitor *
+shell_app_monitor_get_default ()
+{
+  static ShellAppMonitor *instance;
+
+  if (instance == NULL)
+    instance = g_object_new (SHELL_TYPE_APP_MONITOR, NULL);
+
+  return instance;
+}

src/shell-app-monitor.h

@@ -33,7 +33,7 @@ struct _ShellAppMonitorClass
 
 GType shell_app_monitor_get_type (void) G_GNUC_CONST;
 
-ShellAppMonitor* shell_app_monitor_new(void);
+ShellAppMonitor* shell_app_monitor_get_default(void);
 
 /* Get the most popular applications for a given activity */
 GSList *shell_app_monitor_get_most_used_apps (ShellAppMonitor *monitor,

src/shell-app-system.c

@@ -299,3 +299,19 @@ shell_app_system_get_all_settings (ShellAppSystem *monitor)
 {
   return monitor->priv->cached_setting_ids;
 }
+
+/**
+ * shell_app_system_get_default:
+ *
+ * Return Value: (transfer none): The global #ShellAppSystem singleton
+ */
+ShellAppSystem *
+shell_app_system_get_default ()
+{
+  static ShellAppSystem *instance = NULL;
+
+  if (instance == NULL)
+    instance = g_object_new (SHELL_TYPE_APP_SYSTEM, NULL);
+
+  return instance;
+}

src/shell-app-system.h

@@ -29,7 +29,7 @@ struct _ShellAppSystemClass
 };
 
 GType shell_app_system_get_type (void) G_GNUC_CONST;
-ShellAppSystem* shell_app_system_new(void);
+ShellAppSystem* shell_app_system_get_default(void);
 
 GSList *shell_app_system_get_applications_for_menu (ShellAppSystem *system, const char *menu);